Difference Between Mysql and Oracle
When we use the database of Mysql and Oracle we will find there are many differences between them.Now let us have a look at these differences.
1. Oracle is a large database and Mysql is a small and medium databases, Oracle's market share is 40%, Mysql only about 20%, at the same time the Mysql is open source but Oracle price is very high.
2. Oracle support large concurrent and large views, is the best OLTP tools.
3.Installation space is great different. Mysql after installation is only 152M while Oracle is about 3G.And running Oracle will occupy special more memory space and machine performance.
4.Oracle also is different from Mysql on operating.
(1) Handling of the automatic growth data type
MYSQL contains the automatic growth data type.It will not operate this field when inserting records ,and will automatically get the data value.Oracle does not contain the automatic growth data type.Need to establish an automatic increase of the sequence number.When inserting record, the next value of the sequence number should be assigned to this field.
(2)Processing of single quotes
MYSQL can use the double quotes but ORACLE can only use the single quotes.
(3)SQL statements of Processing turning pages
The SQL statement of processing turning pages in MYSQL is relatively simple,using LIMIT to start position and record numbers.But the SQL statement of processing turning pages in ORACLE is more cumbersome.Each result set only a ROWNUM fields marked its location, and can only use ROWNUM <100 but not to use ROWNUM> 80.
(4)Long string processing
The long string processing in ORACLE also is special.The maximum operable string length is less than or equal 4000 using INSERT and UPDATE .If you want to insert a longer string, consider to use the CLOB type field .To insert modify records must be done the judgments of non-empty, and the length.For the empty field value and the field value exceeding length should be warned to return to the last operation.
(5)Handling of null characters
MYSQL contains non-empty fields and empty content,but ORACLE defines a non-empty fields will not allow the empty contents.
(6)The fuzzy comparison of strings
MYSQL uses the field name like '%string%',ORACLE also uses the field name like '%string%' but this method does not use an index, in addition not fast enough.Using the ORACLE function string comparison function instr (field name, 'string')> 0 will get a more accurate search result.
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